Trait signature_core::lib::convert::AsRef 1.0.0[−][src]
Used to do a cheap reference-to-reference conversion.
This trait is similar to AsMut which is used for converting between mutable references.
If you need to do a costly conversion it is better to implement From with type
&T or write a custom function.
AsRef has the same signature as Borrow, but Borrow is different in few aspects:
- Unlike
AsRef,Borrowhas a blanket impl for anyT, and can be used to accept either a reference or a value. Borrowalso requires thatHash,EqandOrdfor borrowed value are equivalent to those of the owned value. For this reason, if you want to borrow only a single field of a struct you can implementAsRef, but notBorrow.
Note: This trait must not fail. If the conversion can fail, use a
dedicated method which returns an Option<T> or a Result<T, E>.
Generic Implementations
AsRefauto-dereferences if the inner type is a reference or a mutable reference (e.g.:foo.as_ref()will work the same iffoohas type&mut Fooor&&mut Foo)
Examples
By using trait bounds we can accept arguments of different types as long as they can be
converted to the specified type T.
For example: By creating a generic function that takes an AsRef<str> we express that we
want to accept all references that can be converted to &str as an argument.
Since both String and &str implement AsRef<str> we can accept both as input argument.
fn is_hello<T: AsRef<str>>(s: T) { assert_eq!("hello", s.as_ref()); } let s = "hello"; is_hello(s); let s = "hello".to_string(); is_hello(s);
Required methods
Loading content...Implementations on Foreign Types
impl<T, N> AsRef<[T]> for GenericArray<T, N> where
N: ArrayLength<T>,
impl<T, N> AsRef<[T]> for GenericArray<T, N> where
N: ArrayLength<T>, impl<T> AsRef<[T; 32]> for GenericArray<T, UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>>
impl<T> AsRef<[T; 32]> for GenericArray<T, UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>>impl<O, V> AsRef<BitSlice<O, <V as BitView>::Store>> for BitArray<O, V> where
V: BitView,
O: BitOrder,
impl<O, V> AsRef<BitSlice<O, <V as BitView>::Store>> for BitArray<O, V> where
V: BitView,
O: BitOrder, pub fn as_ref(&self) -> &BitSlice<O, <V as BitView>::Store>
impl<'_, O, T> AsRef<BitSlice<O, T>> for Iter<'_, O, T> where
T: BitStore,
O: BitOrder,
impl<'_, O, T> AsRef<BitSlice<O, T>> for Iter<'_, O, T> where
T: BitStore,
O: BitOrder,